1. Field of the Invention
This invention relates to insulators for fitment between tubes and building members through which the tubes pass, and in particular to a folding insulator that is reversibly foldable to fit around tubes of two different diameters.
2. Description of the Related Art
In residential and commercial plumbing applications, pipes and other tubes often pass through openings in wall studs, joists and other building members. The building members may be wood or metal. If the tube is allowed to rest against the building member, undesirable noise will be produced by sliding contact between the tube and the building member as the tube expands and contracts due to temperature changes. Furthermore, if the building member is metal, corrosion caused by contact between dissimilar metals may form on copper tubes. Heat from hot water pipes may also be lost through conduction to the building members.
It is known to insulate and isolate tubes from building members by inserting an insulator into the opening in the building member around the tube. An insulator typically comprises a plastic toroid or “doughnut” which fits around the tube inside the opening. The insulator is often split so that it may be placed onto a tube along the length of the tube and not just from the ends. In electrical applications, similar insulators may be used to isolate tubes such as conduit and cable from building members.
A problem with current insulators is that they are generally tube size specific, and therefore a contractor must stock a supply of insulators for each size tube that he or she normally encounters. For example, a plumbing contractor would need a supply of insulators for both ½ inch and ¾ inch CTS pipe to complete most jobs.
Another problem is that an insulator made for use with wooden building members may not work with metal building members, and vise versa. Wooden building members are typically 1½ inches thick whereas metal building members only provide a thin web of metal to fasten the insulator to. Furthermore, the standard openings used when running tube through wood and metal building members are different. Wooden building members are typically drilled with one and three-eighths inch openings whereas the tools used to punch openings in metal building members produce a one and eleven thirty seconds inch opening.
What is needed is an insulator which can be used with more than one size of tube, and preferably one which can be used with both wood and metal building members